Publications by authors named "Andrew R Lloyd"

149 Publications

Evaluating the prevention benefit of HCV treatment: Modelling the SToP-C treatment as prevention study in prisons.

Hepatology 2021 Jun 9. Epub 2021 Jun 9.

Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.

Background & Aims: Between 2014-2019, the SToP-C trial observed a halving in HCV incidence in four Australian prisons following scale-up of direct-acting antiviral (DAA) therapy. However, the contribution of HCV treatment to this decline is unclear due to the study not having a control group. We used modelling to consider this question.

Approach & Results: We parameterised and calibrated a dynamic model of HCV transmission in prisons to data from each SToP-C prison on incarceration dynamics, injecting drug use, HCV prevalence trends among prison entrants, baseline HCV incidence before treatment scale-up, and subsequent HCV treatment scale-up. The model projected the decrease in HCV incidence resulting from increases in HCV treatment and other effects. We assessed whether the model agreed better with observed reductions in HCV incidence overall and by prison if we included HCV treatment scale-up, and its prevention benefits, or did not. The model estimated how much of the observed decrease in HCV incidence was due to HCV treatment in prison. The model projected a decrease in HCV incidence of 48.5% (95% uncertainty interval [UI] 41.9-54.1%) following treatment scale-up across the four prisons, agreeing with the observed HCV incidence decrease (47.6%, 95% confidence interval 23.4-64.2%) from the SToP-C trial. Without any in-prison HCV treatment, the model indicated that incidence would have decreased by 7.2% (95%UI -0.3-13.6%). This suggests 85.1% (95%UI 72.6-100.6%) of the observed halving in incidence was from HCV treatment scale-up, with the remainder from observed decreases in HCV prevalence among prison entrants (14.9%; 95%UI -0.6-27.4%).

Conclusions: Our results demonstrate the prevention benefits of scaling up HCV treatment in prison settings. Prison-based DAA scale-up should be an important component of HCV elimination strategies.
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http://dx.doi.org/10.1002/hep.32002DOI Listing
June 2021

Hepatitis C Virus Epitope Immunodominance and B Cell Repertoire Diversity.

Viruses 2021 May 25;13(6). Epub 2021 May 25.

Faculty of Medicine, School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia.

Despite the advent of effective, curative treatments for hepatitis C virus (HCV), a preventative vaccine remains essential for the global elimination of HCV. It is now clear that the induction of broadly neutralising antibodies (bNAbs) is essential for the rational design of such a vaccine. This review details the current understanding of epitopes on the HCV envelope, characterising the potency, breadth and immunodominance of antibodies induced against these epitopes, as well as describing the interactions between B-cell receptors and HCV infection, with a particular focus on bNAb heavy and light chain variable gene usage. Additionally, we consider the importance of a public repertoire for antibodies against HCV, compiling current knowledge and suggesting that further research in this area may be critical to the rational design of an effective HCV vaccine.
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http://dx.doi.org/10.3390/v13060983DOI Listing
May 2021

Evaluation of hepatitis C treatment-as-prevention within Australian prisons (SToP-C): a prospective cohort study.

Lancet Gastroenterol Hepatol 2021 Jul 7;6(7):533-546. Epub 2021 May 7.

The Kirby Institute, UNSW Sydney, Sydney, NSW, Australia. Electronic address:

Background: Limited empirical evidence exists for the effectiveness of hepatitis C virus (HCV) treatment-as-prevention. The Surveillance and Treatment of Prisoners with hepatitis C (SToP-C) study aimed to assess the effect of HCV treatment-as-prevention in the prison setting.

Methods: SToP-C was a prospective study, including a before-and-after analysis, within a cohort of people incarcerated in two maximum-security prisons (male) and two medium-security prisons (one male, one female) in New South Wales, Australia. All prison inmates aged at least 18 years were eligible for enrolment. After HCV testing, participants were monitored for risk behaviours and HCV infection, among three sub-populations: uninfected (HCV antibody-negative); previously infected (HCV antibody-positive, HCV RNA-negative); and infected (HCV antibody and HCV RNA-positive). Uninfected participants were followed up every 3-6 months to detect HCV primary infection and previously infected participants were followed up every 3-6 months to detect re-infection. Participants with HCV infection were assessed for treatment, initially standard-of-care treatment (administered by prison health services) from 2014 to mid-2017, then direct-acting antiviral (DAA) treatment scale-up from mid-2017 onwards (12 weeks of sofosbuvir plus velpatasvir, administered through SToP-C). Participants were followed up until study closure in November, 2019. The primary study outcome was HCV incidence before and after DAA treatment scale-up among participants at risk of HCV primary infection or re-infection. This study is registered with ClinicalTrials.gov, NCT02064049.

Findings: Between Oct 30, 2014, and Sept 30, 2019, 3691 participants were enrolled in the SToP-C study. 719 (19%) participants had detectable HCV RNA, 2240 (61%) were at risk of primary HCV infection, and 725 (20%) were at risk of re-infection at baseline. DAA treatment was initiated in 349 (70%) of 499 eligible participants during the treatment scale-up period. The HCV incidence analysis comprised 1643 participants at risk of HCV infection or re-infection during longitudinal follow-up (median age 33 years [IQR 27-42]; 1350 [82%] male). 487 (30%) of 1643 participants reported injecting drugs in prison. HCV incidence decreased from 8·31 per 100 person-years in the pre-treatment scale-up period to 4·35 per 100 person-years in the post-treatment scale-up period (incidence rate ratio [IRR] 0·52 [95% CI 0·36-0·78]; p=0·0007). The incidence of primary infection decreased from 6·64 per 100 person-years in the pre-treatment scale-up period to 2·85 per 100 person-years in the post-treatment scale-up period (IRR 0·43 [95% CI 0·25-0·74]; p=0·0019), whereas the incidence of re-infection decreased from 12·36 per 100 person-years to 7·27 per 100 person-years (0·59 [0·35-1·00]; p=0·050). Among participants reporting injecting drugs during their current imprisonment, the incidence of primary infection decreased from 39·08 per 100 person-years in the pre-treatment scale-up period to 14·03 per 100 person-years in the post-treatment scale-up period (IRR 0·36 [95% CI 0·16-0·80]; p=0·0091), and the incidence of re-infection decreased from 15·26 per 100 person-years to 9·34 per 100 person-years (0·61 [0·34-1·09]; p=0·093). The adjusted analysis (adjusted for age, Indigenous Australian ethnicity, duration of stay in prison, previous imprisonment, injecting drug use status, and prison site) indicated a significant reduction in the risk of HCV infection between the pre-DAA treatment scale-up and post-DAA treatment scale-up periods (adjusted hazard ratio 0·50 [95% CI 0·33-0·76]; p=0·0014).

Interpretation: DAA treatment scale-up was associated with reduced HCV incidence in prison, indicative of a beneficial effect of HCV treatment-as-prevention in this setting. These findings support broad DAA treatment scale-up within incarcerated populations.

Funding: Australian National Health and Medical Research Council Partnership Project Grant and Gilead Sciences.
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http://dx.doi.org/10.1016/S2468-1253(21)00077-7DOI Listing
July 2021

Hepatitis C elimination among people incarcerated in prisons: challenges and recommendations for action within a health systems framework.

Lancet Gastroenterol Hepatol 2021 05;6(5):391-400

Viral Immunology Systems Program, Kirby Institute for Infection and Immunity, University of New South Wales, Sydney, NSW, Australia.

Hepatitis C virus (HCV) is a global public health problem in correctional settings. The International Network on Health and Hepatitis in Substance Users-Prisons Network is a special interest group committed to advancing scientific knowledge exchange and advocacy for HCV prevention and care in correctional settings. In this Review, we highlight seven priority areas and best practices for improving HCV care in correctional settings: changing political will, ensuring access to HCV diagnosis and testing, promoting optimal models of HCV care and treatment, improving surveillance and monitoring of the HCV care cascade, reducing stigma and tackling the social determinants of health inequalities, implementing HCV prevention and harm reduction programmes, and advancing prison-based research.
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http://dx.doi.org/10.1016/S2468-1253(20)30365-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8118192PMC
May 2021

Human CD8 T-stem cell memory subsets phenotypic and functional characterization are defined by expression of CD122 or CXCR3.

Eur J Immunol 2021 Apr 12. Epub 2021 Apr 12.

Viral Immunology Systems Program (VISP), The Kirby Institute, University of New South Wales, Sydney, Australia.

Long-lived T-memory stem cells (T ) are key to both naturally occurring and vaccine-conferred protection against infection. These cells are characterized by the CD45RA CCR7 CD95 phenotype. Significant heterogeneity within the T population is recognized, but distinguishing surface markers and functional characterization of potential subsets are lacking. Human CD8 T subsets were identified in healthy subjects who had been previously exposed to CMV or Influenza (Flu) virus in flow cytometry by expression of CD122 or CXCR3, and then characterized in proliferation, multipotency, self-renewal, and intracellular cytokine production (TNF-α, IL-2, IFN-γ), together with transcriptomic profiles. The T CD122 -expressing subset (versus CD122 ) demonstrated greater proliferation, greater multipotency, and enhanced polyfunctionality with higher frequencies of triple positive (TNF-α, IL-2, IFN-γ) cytokine-producing cells upon exposure to recall antigen. The T CXCR3 subpopulation also had increased proliferation and polyfunctional cytokine production. Transcriptomic analysis further showed that the T CD122 population had increased expression of activation and homing molecules, such as Ccr6, Cxcr6, Il12rb, and Il18rap, and downregulated cell proliferation inhibitors, S100A8 and S100A9. These data reveal that the T CD122 phenotype is associated with increased proliferation, enhanced multipotency and polyfunctionality with an activated memory-cell like transcriptional profile, and hence, may be favored for induction by immunization and for adoptive immunotherapy.
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http://dx.doi.org/10.1002/eji.202049057DOI Listing
April 2021

Long-term persistence of RBD memory B cells encoding neutralizing antibodies in SARS-CoV-2 infection.

Cell Rep Med 2021 Apr 14;2(4):100228. Epub 2021 Mar 14.

The Kirby Institute, UNSW Australia, Sydney, NSW, Australia.

Considerable concerns relating to the duration of protective immunity against severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) exist, with evidence of antibody titers declining rapidly after infection and reports of reinfection. Here, we monitor the antibody responses against SARS-CoV-2 receptor-binding domain (RBD) for up to 6 months after infection. While antibody titers are maintained, ∼13% of the cohort's neutralizing responses return to background. However, encouragingly, in a selected subset of 13 participants, 12 have detectable RBD-specific memory B cells and these generally are increasing out to 6 months. Furthermore, we are able to generate monoclonal antibodies with SARS-CoV-2 neutralizing capacity from these memory B cells. Overall, our study suggests that the loss of neutralizing antibodies in plasma may be countered by the maintenance of neutralizing capacity in the memory B cell repertoire.
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http://dx.doi.org/10.1016/j.xcrm.2021.100228DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7955929PMC
April 2021

Adaptation of Oxford Nanopore technology for hepatitis C whole genome sequencing and identification of within-host viral variants.

BMC Genomics 2021 Mar 2;22(1):148. Epub 2021 Mar 2.

Kirby Institute, UNSW Sydney, Sydney, NSW, 2052, Australia.

Background: Hepatitis C (HCV) and many other RNA viruses exist as rapidly mutating quasi-species populations in a single infected host. High throughput characterization of full genome, within-host variants is still not possible despite advances in next generation sequencing. This limitation constrains viral genomic studies that depend on accurate identification of hemi-genome or whole genome, within-host variants, especially those occurring at low frequencies. With the advent of third generation long read sequencing technologies, including Oxford Nanopore Technology (ONT) and PacBio platforms, this problem is potentially surmountable. ONT is particularly attractive in this regard due to the portable nature of the MinION sequencer, which makes real-time sequencing in remote and resource-limited locations possible. However, this technology (termed here 'nanopore sequencing') has a comparatively high technical error rate. The present study aimed to assess the utility, accuracy and cost-effectiveness of nanopore sequencing for HCV genomes. We also introduce a new bioinformatics tool (Nano-Q) to differentiate within-host variants from nanopore sequencing.

Results: The Nanopore platform, when the coverage exceeded 300 reads, generated comparable consensus sequences to Illumina sequencing. Using HCV Envelope plasmids (~ 1800 nt) mixed in known proportions, the capacity of nanopore sequencing to reliably identify variants with an abundance as low as 0.1% was demonstrated, provided the autologous reference sequence was available to identify the matching reads. Successful pooling and nanopore sequencing of 52 samples from patients with HCV infection demonstrated its cost effectiveness (AUD$ 43 per sample with nanopore sequencing versus $100 with paired-end short read technology). The Nano-Q tool successfully separated between-host sequences, including those from the same subtype, by bulk sorting and phylogenetic clustering without an autologous reference sequence (using only a subtype-specific generic reference). The pipeline also identified within-host viral variants and their abundance when the parameters were appropriately adjusted.

Conclusion: Cost effective HCV whole genome sequencing and within-host variant identification without haplotype reconstruction are potential advantages of nanopore sequencing.
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http://dx.doi.org/10.1186/s12864-021-07460-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7923462PMC
March 2021

Regulation of the acute sickness response by the P2X7 receptor.

J Infect Dis 2021 Jan 20. Epub 2021 Jan 20.

Viral Immunology Systems Program, Kirby Institute, University of NSW, Sydney, Australia.

Introduction: The acute sickness response to infection is a stereotyped set of illness manifestations initiated by pro-inflammatory signals in the periphery, but mediated centrally. P2X7 is a highly polymorphic gene encoding an ATP-gated cationic pore, widely expressed on immune cells and the brain, and regulating the NLRP3 inflammasome, as well as diverse neural functions.

Methods: Associations between P2X7 genotype, pore activity, and illness manifestations were examined in a cohort with acute viral and bacterial infections (n=484). Genotyping of 12 P2X7 function-modifying single nucleotide polymorphisms (SNPs) was used to identify haplotypes and diplotypes. Leucocyte pore activity was measured by uptake of the fluorescent dye, Yo-Pro-1 and by ATP-induced interleukin (IL)-1β release. Associations were sought with scores describing the symptom domains, or endophenotypes, derived from principal components analysis.

Results: Among the 12 SNPs, a four-SNP haplotype block with five variants was found in 99.5% of the subjects. These haplotypes and diplotypes were closely associated with variations in pore activity and IL-1β production. Homozygous diplotypes were associated with overall illness severity as well as fatigue, pain and mood disturbances.

Conclusion: P2X7 signalling plays a significant role in the acute sickness response to infection, likely acting in both the immune system and the brain.
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http://dx.doi.org/10.1093/infdis/jiab027DOI Listing
January 2021

The severity of the pathogen-induced acute sickness response is affected by polymorphisms in genes of the NLRP3 inflammasome pathway.

Brain Behav Immun 2021 03 9;93:186-193. Epub 2021 Jan 9.

Kirby Institute, The University of New South Wales, Sydney (UNSW Sydney), Wallace Wurth Building, High St, Kensington, NSW 2052, Australia. Electronic address:

The acute sickness response (ASR) is a stereotyped set of symptoms including fatigue, pain, and disturbed mood, which are present in most acute infections. The immunological mechanisms of the ASR are conserved, with variations in severity determined partly by the pathogen, but also by polymorphisms in host genes. The ASR was characterised in three different serologically-confirmed acute infections in Caucasians (n = 484) across four symptom domains or endophenotypes (termed 'Fatigue', 'Musculoskeletal pain', 'Mood disturbance', and 'Acute sickness'). Correlations were sought with functional single nucleotide polymorphisms in the NLRP3 inflammasone pathway and severity of the endophenotypes. Individuals with severe Fatigue, Musculoskeletal pain, or Mood endophenotypes were more likely to have prior episodes of significant fatigue (11.4 vs. 3.8%, p = 0.07), pain (14.3 vs. 1.2%, p = 0.001), or Mood disturbance (13 vs 1%, p=0.001), suggesting trait characteristics. The high functioning allele of the rs35829419 SNP in NLRP3 was more common in those with severe Fatigue (OR = 13.3, 95% CI: 1.7-104), particularly in a dominant inheritance pattern (OR = 13.4, 95% CI: 1.8-586.3). In a multivariable analysis assuming dominant inheritance, both rs35829419 and the rs4848306 SNP in Interleukin(IL)-1β, were independently associated with severe Fatigue (OR = 29.6, 95% CI: 2.6-330.9 and OR = 13, 95% CI: 2.7-61.8, respectively). The severity of fatigue in acute infection is influenced by genetic polymorphisms in NLRP3 and IL-1β.
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http://dx.doi.org/10.1016/j.bbi.2021.01.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7794598PMC
March 2021

Violence and hepatitis C transmission in prison-A modified social ecological model.

PLoS One 2020 1;15(12):e0243106. Epub 2020 Dec 1.

The Kirby Institute, UNSW Sydney, Sydney, Australia.

Background: Transmission of hepatitis C virus (HCV) among the prisoner population is most frequently associated with sharing of non-sterile injecting equipment. Other blood-to-blood contacts such as tattooing and physical violence are also common in the prison environment, and have been associated with HCV transmission. The context of such non-injecting risk behaviours, particularly violence, is poorly studied. The modified social-ecological model (MSEM) was used to examine HCV transmission risk and violence in the prison setting considering individual, network, community and policy factors.

Methods: The Australian Hepatitis C Incidence and Transmission Study in prisons (HITS-p) cohort enrolled HCV uninfected prisoners with injecting and non-injecting risk behaviours, who were followed up for HCV infection from 2004-2014. Qualitative interviews were conducted within 23 participants; of whom 13 had become HCV infected. Deductive analysis was undertaken to identify violence as risk within prisons among individual, network, community, and public policy levels.

Results: The risk context for violence and HCV exposure varied across the MSEM. At the individual level, participants were concerned about blood contact during fights, given limited scope to use gloves to prevent blood contamination. At the network level, drug debt and informing on others to correctional authorities, were risk factors for violence and potential HCV transmission. At the community level, racial influence, social groupings, and socially maligned crimes like sexual assault of children were identified as possible triggers for violence. At the policy level, rules and regulations by prison authority influenced the concerns and occurrence of violence and potential HCV transmission.

Conclusion: Contextual concerns regarding violence and HCV transmission were evident at each level of the MSEM. Further evidence-based interventions targeted across the MSEM may reduce prison violence, provide opportunities for HCV prevention when violence occurs and subsequent HCV exposure.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0243106PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7707477PMC
January 2021

Single molecule, near full-length genome sequencing of dengue virus.

Sci Rep 2020 10 23;10(1):18196. Epub 2020 Oct 23.

School of Medical Sciences, University of New South Wales, Sydney, Australia.

Current methods for dengue virus (DENV) genome amplification, amplify parts of the genome in at least 5 overlapping segments and then combine the output to characterize a full genome. This process is laborious, costly and requires at least 10 primers per serotype, thus increasing the likelihood of PCR bias. We introduce an assay to amplify near full-length dengue virus genomes as intact molecules, sequence these amplicons with third generation "nanopore" technology without fragmenting and use the sequence data to differentiate within-host viral variants with a bioinformatics tool (Nano-Q). The new assay successfully generated near full-length amplicons from DENV serotypes 1, 2 and 3 samples which were sequenced with nanopore technology. Consensus DENV sequences generated by nanopore sequencing had over 99.5% pairwise sequence similarity to Illumina generated counterparts provided the coverage was > 100 with both platforms. Maximum likelihood phylogenetic trees generated from nanopore consensus sequences were able to reproduce the exact trees made from Illumina sequencing with a conservative 99% bootstrapping threshold (after 1000 replicates and 10% burn-in). Pairwise genetic distances of within host variants identified from the Nano-Q tool were less than that of between host variants, thus enabling the phylogenetic segregation of variants from the same host.
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http://dx.doi.org/10.1038/s41598-020-75374-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7584602PMC
October 2020

The role of social capital in facilitating hepatitis C treatment scale-up within a treatment-as-prevention trial in the male prison setting.

Addiction 2021 05 18;116(5):1162-1171. Epub 2020 Oct 18.

Centre for Social Research in Health, UNSW Sydney, Sydney, NSW, Australia.

Background And Aims: Hepatitis C (HCV) is a global public health concern, particularly in the prison setting where prevalence is substantially higher than in the general population. Direct-acting antivirals have changed the treatment landscape, allowing for treatment scale-up efforts potentially sufficient to achieve prevention of onward transmission (treatment-as-prevention). The Surveillance and Treatment of Prisoners with hepatitis C (SToP-C) study was the first trial to examine the efficacy of HCV treatment-as-prevention in the prison setting. Social capital is a social resource which has been found to influence health outcomes. This qualitative study sought to understand the role of social capital within an HCV treatment-as-prevention trial in the prison setting.

Design: Semi-structured in-depth interviews were undertaken with participants recruited from the SToP-C study following HCV treatment completion (with cure).

Setting: Three male correctional centres in New South Wales, Australia (including two maximum-security and one minimum-security).

Participants: Twenty-three men in prison participated in semi-structured interviews.

Measurements: Thematic analysis of transcripts was completed using a social capital framework, which enabled exploration of the ways in which bonding, bridging and linking social capital promoted or inhibited HCV treatment uptake within a treatment-as-prevention trial.

Findings: Social capital fostered HCV treatment uptake within an HCV treatment-as-prevention trial in the prison setting. Bonding social capital encouraged treatment uptake and alleviated concerns of side effects, bridging social capital supported prison-wide treatment uptake, and linking social capital fostered trust in study personnel (including nurses and correctional officers), thereby enhancing treatment engagement.

Conclusions: Social capital, including bonding, bridging and linking, can play an important role in hepatitis C treatment-as-prevention efforts within the male prison setting.
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http://dx.doi.org/10.1111/add.15277DOI Listing
May 2021

Self-reported health, lifestyle and social circumstances of Australian adult cancer survivors: A propensity score weighted cross-sectional study.

Cancer Epidemiol 2020 08 29;67:101773. Epub 2020 Jun 29.

Department of Medical Oncology, Nelune Cancer Centre, Prince of Wales Hospital, Sydney, Australia.

Background: With the prevalence of cancer survivors increasing, their unique needs must be better understood. We examined the health, lifestyles and social circumstances of adults with and without a history of cancer.

Methods: We performed a cross-sectional study, using exposure and outcome data from the baseline survey (2006-2009) of participants in the 45 and Up Study, a prospective cohort study in New South Wales, Australia. We compared 20,811 cancer registry-verified adult cancer survivors with 207,148 participants without a history of cancer using propensity score weighting and accounting for multiple testing. The propensity weighting included age, sociodemographic factors and number of self-reported co-morbidities.

Results: Cancer survivors were more likely to report poorer physical and psychological health and quality of life compared to those without a cancer history, with most deficits still evident more than 10 years after cancer diagnosis. Cancer survivors were more likely to have a higher body mass index, but were less likely to smoke. Cancer survivors had greater functional limitations, including sexual, and were less likely to work full time, volunteer and spend time outdoors. Their social connectedness was, however, similar. Those with haematological cancer, lung cancer, or distant metastases, and those diagnosed at an older age, had the greatest health deficits and functional limitations.

Conclusions: A history of cancer is associated with poorer health and less paid and unpaid work. Our findings reinforce the importance of routine long-term, integrated multidisciplinary care for cancer survivors and indicate the subgroups with the greatest unmet needs.
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http://dx.doi.org/10.1016/j.canep.2020.101773DOI Listing
August 2020

Anti-envelope antibody responses in highly exposed seronegative individuals may be associated with protection from HCV infection.

J Viral Hepat 2020 10 17;27(10):1012-1021. Epub 2020 Jun 17.

Viral Immunology Systems Program, The Kirby Institute, The University of New South Wales, Sydney, New South Wales, Australia.

In rare cases, individuals with a history of long-term injecting drug use remain seronegative and aviraemic, despite prolonged and likely repeated exposure to Hepatitis C virus (HCV) through high-risk behaviour. We describe anti-HCV Envelope (E) antibody responses in a prospective cohort of carefully defined highly exposed but uninfected subjects (HESN) and comparison subjects who were also high risk and uninfected, but rapidly became HCV infected (Incident). Longitudinally collected samples from HESN cases (n = 22) were compared to Incident controls (n = 22). IgG, IgM and IgA from sera were tested by ELISA to genotype 1a and 3a E glycoproteins, and recombinant genotype 1a E2 antigen. IgG subclass isotyping was performed for those positive for IgG. Virus-neutralizing activity was assessed on HCV pseudoparticles, and HCV E-specific B cells analysed using flow cytometry. A significant minority of HESN cases (n = 10; 45%) had anti-E, predominantly in the IgG2 subclass, which was not found in the pre-infection time point of the Incident cases (n = 1; 5%). A subset of the HESN subjects also had neutralizing activity and HCV-specific B cells detected significantly more than Incident cases pre-infection. In conclusion, the HESN phenotype is associated with IgG2 anti-E antibodies, neutralization activity and HCV E-specific memory B cells. These findings suggest that HESN subjects may be resistant to HCV infection through humoral immune-mediated mechanisms.
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http://dx.doi.org/10.1111/jvh.13339DOI Listing
October 2020

Impact of an Open Access Nationwide Treatment Model on Hepatitis C Virus Antiviral Drug Resistance.

Hepatol Commun 2020 Jun 6;4(6):904-915. Epub 2020 Apr 6.

Storr Liver Centre The Westmead Institute for Medical Research The University of Sydney and Westmead Hospital Sydney Australia.

Direct acting antivirals (DAAs) have revolutionized hepatitis C virus (HCV) treatment, but drug resistance could undermine proposed global elimination targets. Real-world studies are needed to inform the impact of widespread DAA treatment on antiviral resistance in the community. The prevalence and range of posttreatment resistance-associated substitutions (RASs) was determined in Australian patients with open access to DAAs through a wide range of prescribers. NS3, NS5A, and NS5B regions were amplified by polymerase chain reaction and analyzed by population sequencing. Clinically relevant RASs were identified using online databases (ReCALL and Geno2Pheno[hcv]). Of 572 samples, 60% were from genotype 3 and 27% from genotype 1a. Ninety-two percent of people failed a DAA regimen containing an NS5A inhibitor, including 10% with a pangenotype regimen. NS5A RASs were detected in 72% of people with genotype 1 and 80% with genotype 3. For genotype 1, there was a range of RASs across the NS5A region, while for genotype 3, the Y93H RAS predominated (72%). The prevalence of NS3 RASs was higher in people exposed to an NS3 inhibitor (35% vs. 3.9%;  < 0.0001). NS5B resistance was rare, with a single case of sofosbuvir resistance. Multiclass drug resistance was found in 33% of people exposed to both NS3 and NS5A inhibitors. : The high prevalence of NS5A RASs among people failing DAA therapy reinforces the importance of specific retreatment regimens, ideally guided by resistance testing. The impact of multiclass drug resistance on retreatment in people exposed to both NS3 and NS5A inhibitors needs to be assessed in real-world studies. Surveillance for increasing antiviral resistance during treatment scale-up is essential to maintain the efficacy of current DAA regimens.
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http://dx.doi.org/10.1002/hep4.1496DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7262285PMC
June 2020

Chronic fatigue syndrome: progress and possibilities.

Med J Aust 2020 05 5;212(9):428-433. Epub 2020 Apr 5.

Kirby Institute for Infection and Immunity in Society, UNSW, Sydney, NSW.

Chronic fatigue syndrome (CFS) is a prevalent condition affecting about one in 100 patients attending primary care. There is no diagnostic test, validated biomarker, clear pathophysiology or curative treatment. The core symptom of fatigue affects both physical and cognitive activities, and features a prolonged post-activity exacerbation triggered by tasks previously achieved without difficulty. Although several different diagnostic criteria are proposed, for clinical purposes only three elements are required: recognition of the typical fatigue; history and physical examination to exclude other medical or psychiatric conditions which may explain the symptoms; and a restricted set of laboratory investigations. Studies of the underlying pathophysiology clearly implicate a range of different acute infections as a trigger for onset in a significant minority of cases, but no other medical or psychological factor has been reproducibly implicated. There have been numerous small case-control studies seeking to identify the biological basis of the condition. These studies have largely resolved what the condition is not: ongoing infection, immunological disorder, endocrine disorder, primary sleep disorder, or simply attributable to a psychiatric condition. A growing body of evidence suggests CFS arises from functional (non-structural) changes in the brain, but of uncertain character and location. Further functional neuroimaging studies are needed. There is clear evidence for a genetic contribution to CFS from family and twin studies, suggesting that a large scale genome-wide association study is warranted. Despite the many unknowns in relation to CFS, there is significant room for improvement in provision of the diagnosis and supportive care. This may be facilitated via clinician education.
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http://dx.doi.org/10.5694/mja2.50553DOI Listing
May 2020

Incident hepatitis B virus infection and immunisation uptake in Australian prison inmates.

Vaccine 2020 04 6;38(16):3255-3260. Epub 2020 Mar 6.

The Kirby Institute, University of New South Wales, Sydney, Australia; School of Medical Sciences, University of New South Wales, Sydney, Australia.

Introduction: Despite an effective vaccine, hepatitis B virus (HBV) infection continues to impose a large burden of disease globally. Until childhood immunisation achieves high adult population coverage, people who inject drugs (PWID), including prison inmates remain at risk. PWID have a higher prevalence of HBV than the wider population, and lower rates of vaccine-conferred immunity. This study sought to identify the incidence and predictors of HBV transmission and uptake of immunisation in PWID prisoners in Australia.

Methods: Longitudinally collected, stored sera from subjects previously enrolled in a prospective study of hepatitis C in recently incarcerated PWID prisoners (n = 590) were serologically tested for HBV. Interviews recording demographic and behavioural risks were analysed. Multivariate statistical analyses were applied to identify associations of incident infection or immunisation.

Results: Upon imprisonment there were n = 373 (63%) individuals who were HBV susceptible, of whom 140 remained susceptible at the subsequent enrolment into the cohort, and had one or more follow-up visits (a total of 406.73 person years [p.y.]), and so were included in this analysis. There were 7 incident cases of HBV infection (1.7 per 100 p.y.) in this group, with transmission being associated with injecting drug use daily or more often. There were 48 individuals who were successfully immunised (11.8 per 100 p.y.) with younger age and continuous imprisonment predicting this outcome.

Conclusions: The Australian prison environment poses a high risk for HBV infection, and also provides an opportunity for immunisation for PWID. Further efforts are required to improve coverage and prevent ongoing transmissions.
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http://dx.doi.org/10.1016/j.vaccine.2020.02.076DOI Listing
April 2020

Perceptions and concerns of hepatitis C reinfection following prison-wide treatment scale-up: Counterpublic health amid hepatitis C treatment as prevention efforts in the prison setting.

Int J Drug Policy 2020 03 8;77:102693. Epub 2020 Feb 8.

Centre for Social Research in Health, UNSW Sydney, Level 2, Goodsell Building, Sydney NSW 2052, Australia.

Background: Hepatitis C (HCV) infection is highly prevalent within the prison setting. Direct-acting antiviral (DAA) therapies have changed the HCV treatment landscape, offering simple treatment (with minimal side-effects) and high efficacy. These advances have enabled the first real-world study of HCV treatment as prevention (TasP), the Surveillance and Treatment of Prisoners with hepatitis C (SToP-C) study. This paper draws on data from qualitative interviews completed with SToP-C participants following prison-wide DAA treatment scale-up.

Methods: Semi-structured interviews were undertaken with 23 men in prison following HCV treatment completion to identify ongoing risk practices, perceptions of strategies for HCV prevention within the prison setting, experiences of HCV treatment (as prevention), and perceptions of reinfection following cure. Analysis was undertaken using a counterpublic health lens to identify risks and perceptions of reinfection among people treated for HCV within the prison setting.

Results: Participants identified a number of challenges of meaningful HCV 'cure' in the absence of increased access to prevention strategies (e.g., opioid agonist therapy and prison needle syringe programs) along with concerns that 'cure' was only temporary whilst incarcerated. 'Cure' status included self-perceptions of being "clean", while also imposing responsibility on the individual to maintain their 'cure' status.

Conclusion: HCV DAA treatment is provided somewhat under the guise of 'cure is easy', but fails to address the ongoing risk factors experienced by people who inject drugs in prisons, as well as other people in prison who may be at risk of blood-to-blood exposure. Health messaging regarding HCV treatment and treatment for reinfection should be tailored to ensure patient-centred care. Health interventions in prison must address the whole person and the circumstances in which they live, not just the illness.
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http://dx.doi.org/10.1016/j.drugpo.2020.102693DOI Listing
March 2020

Parasympathetic activity is reduced during slow-wave sleep, but not resting wakefulness, in patients with chronic fatigue syndrome.

J Clin Sleep Med 2020 01 27;16(1):19-28. Epub 2019 Nov 27.

School of Psychiatry, Faculty of Medicine, University of New South Wales Sydney, New South Wales, Australia.

Study Objectives: Physiological dearousal characterized by an increase in parasympathetic nervous system activity is important for good-quality sleep. Previous research shows that nocturnal parasympathetic activity (reflected by heart rate variability [HRV]) is diminished in individuals with chronic fatigue syndrome (CFS), suggesting hypervigilant sleep. This study investigated differences in nocturnal autonomic activity across sleep stages and explored the association of parasympathetic activity with sleep quality and self-reported physical and psychological wellbeing in individuals with CFS.

Methods: Twenty-four patients with medically diagnosed CFS, and 24 matched healthy control individuals participated. Electroencephalography and HRV were recorded during sleep in participants' homes using a minimally invasive ambulatory device. Questionnaires were used to measure self-reported wellbeing and sleep quality.

Results: Sleep architecture in patients with CFS differed from that of control participants in slower sleep onset, more awakenings, and a larger proportion of time spent in slow-wave sleep (SWS). Linear mixed-model analyses controlling for age revealed that HRV reflecting parasympathetic activity (normalized high frequency power) was reduced in patients with CFS compared to control participants, particularly during deeper stages of sleep. Poorer self-reported wellbeing and sleep quality was associated with reduced parasympathetic signaling during deeper sleep, but not during wake before sleep, rapid eye movement sleep, or with the proportion of time spent in SWS.

Conclusions: Autonomic hypervigilance during the deeper, recuperative stages of sleep is associated with poor quality sleep and self-reported wellbeing. Causal links need to be confirmed but provide potential intervention opportunities for the core symptom of unrefreshing sleep in CFS.
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http://dx.doi.org/10.5664/jcsm.8114DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7053003PMC
January 2020

Envelope-Specific IgG3 and IgG1 Responses Are Associated with Clearance of Acute Hepatitis C Virus Infection.

Viruses 2020 01 8;12(1). Epub 2020 Jan 8.

Viral Immunology Systems Program, The Kirby Institute, Sydney, NSW 2052, Australia.

Hepatitis C virus (HCV) can be cleared naturally in a subset of individuals. However, the asymptomatic nature of acute HCV infection makes the study of the early immune response and defining the correlates of protection challenging. Despite this, there is now strong evidence implicating the humoral immune response, specifically neutralising antibodies, in determining the clearance or chronicity outcomes of primary HCV infection. In general, immunoglobulin G (IgG) plays the major role in viral neutralisation. However, there are limited investigations of anti-HCV envelope protein 2 (E2) isotypes (IgM, IgG, IgA) and IgG subclasses (IgG1-4) in early HCV infection. In this study, using a rare cohort of 14 very recently HCV-infected individuals (4-45 days) with varying disease outcome ( = 7 clearers), the timing and potency of anti-HCV E2 isotypes and IgG subclasses were examined longitudinally, in relation to neutralising antibody activity. Clearance was associated with anti-E2 IgG, specifically IgG1 and IgG3, and appeared essential to prevent the emergence of new HCV variants and the chronic infection outcome. Interestingly, these IgG responses were accompanied by IgM antibodies and were associated with neutralising antibody activity in the subjects who cleared infection. These findings provide novel insights into the early humoral immune response characteristics associated with HCV disease outcome.
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http://dx.doi.org/10.3390/v12010075DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019651PMC
January 2020

Physical and mental fatigue across the menstrual cycle in women with and without generalised anxiety disorder.

Horm Behav 2020 02 8;118:104667. Epub 2020 Jan 8.

School of Psychology, The University of New South Wales, Sydney, New South Wales, Australia.

Subjective, disabling fatigue is a common complaint and a key feature of numerous medical conditions, and is a transdiagnostic feature of psychiatric disorders. Despite physical and mental fatigue being associated with functional impairment and reduced quality of life, little is understood about its underlying mechanisms or modulating factors. Women commonly experience exacerbation of other (non-fatigue related) psychiatric symptoms during the luteal phase of the menstrual cycle, and report greater fatigue prevalence compared to men. It is therefore plausible that subjective fatigue may similarly fluctuate across the menstrual cycle. Here we compared physical and mental fatigue in the early-follicular (lower ovarian hormones) and mid-luteal (higher ovarian hormones) phases of a single menstrual cycle, while controlling for sleep disruption, in women with (n = 18) and without (non-anxious; n = 20) generalised anxiety disorder (GAD). As expected, women with GAD reported greater physical and mental fatigue than healthy women. Further, although there were no changes in physical fatigue from the early-follicular to mid-luteal phases in both groups, mental fatigue in non-anxious women increased to levels equivalent to those experienced by their GAD counterparts in the mid-luteal phase. Although salivary levels of estradiol and progesterone increased from the early-follicular to mid-luteal phase, hormones did not significantly predict fatigue in either phase. These findings are consistent with the exacerbations of state anxiety and mood disturbance recognised to occur in the luteal phase of the menstrual cycle. We speculate that increased mental fatigue in the luteal phase may represent a vulnerable period for the development and maintenance of psychiatric disorders, potentially via compromised emotional regulation.
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http://dx.doi.org/10.1016/j.yhbeh.2019.104667DOI Listing
February 2020

B cell immunodominance in primary hepatitis C virus infection.

J Hepatol 2020 04 28;72(4):670-679. Epub 2019 Nov 28.

School of Medical Sciences and the Kirby Institute, Faculty of Medicine, UNSW Sydney, Sydney, NSW 2052, Australia. Electronic address:

Background & Aims: Neutralising antibodies (NAbs) play a key role in clearance of HCV. NAbs have been isolated and mapped to several domains on the HCV envelope proteins. However, the immunodominance of these epitopes in HCV infection remains unknown, hindering efforts to elicit optimal epitope-specific responses. Furthermore, it remains unclear which epitope-specific responses are associated with broad NAb (bNAb) activity in primary HCV infection. The aim of this study was to define B cell immunodominance in primary HCV, and its implications on neutralisation breadth and clearance.

Methods: Using samples from 168 patients with primary HCV infection, the antibody responses targeted 2 immunodominant domains, termed domains B and C. Genotype 1 and 3 infections were associated with responses targeted towards different bNAb domains.

Results: No epitopes were uniquely targeted by clearers compared to those who developed chronic infection. Samples with bNAb activity were enriched for multi-specific responses directed towards the epitopes antigenic region 3, antigenic region 4, and domain D, and did not target non-neutralising domains.

Conclusions: This study outlines for the first time a clear NAb immunodominance profile in primary HCV infection, and indicates that it is influenced by the infecting virus. It also highlights the need for a vaccination strategy to induce multi-specific responses that do not target non-neutralising domains.

Lay Summary: Neutralising antibodies will likely form a key component of a protective hepatitis C virus vaccine. In this work we characterise the predominant neutralising and non-neutralising antibody (epitope) targets in acute hepatitis C virus infection. We have defined the natural hierarchy of epitope immunodominance, and demonstrated that viral genotype can impact on this hierarchy. Our findings highlight key epitopes that are associated with broadly neutralising antibodies, and the deleterious impact of mounting a response towards some of these domains on neutralising breadth. These findings should guide future efforts to design immunogens aimed at generating neutralising antibodies with a vaccine candidate.
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http://dx.doi.org/10.1016/j.jhep.2019.11.011DOI Listing
April 2020

Combined treatment and prevention strategies for hepatitis C virus elimination in the prisons in New South Wales: a modelling study.

Addiction 2020 05 12;115(5):901-913. Epub 2019 Nov 12.

Viral Immunology Systems Program, Kirby Institute, University of New South Wales, Sydney, NSW, Australia.

Background And Aims: Australia is currently on track to meet the World Health Organization (WHO) global hepatitis C virus (HCV) elimination goals by 2030, reflecting universal subsidized access to testing and direct-acting antiviral (DAA) treatment. In New South Wales, DAA treatment in prisons has scaled-up substantially, with 1000 prisoners treated in 2017. However, HCV prevalence and incidence in this setting is high, which could undermine elimination efforts. This study aimed to test the preventative effects of DAA treatment scale-up, opiate substitution treatment (OST) and needle and syringe programme (NSP) strategies for prisons.

Design: Modelling study using an individual-based mathematical model of a typical prison setting. The model was calibrated against Australian epidemiological data sets and executed in-prison events for each individual daily, including movements between prisons, changes in risk behaviour and uptake of prevention measures such as OST and NSP, as well as DAA treatment. Scenarios were projected from 2018 to 2030.

Setting: New South Wales prisons.

Participants: New South Wales prisoners.

Measurements: Variables including prison populations, prevalence and incidence rate were calculated. Prisoners were described by demographic characteristics, HCV infection history, risk behaviours and accessing treatment and prevention measures in varied security settings.

Findings: Increasing the number of prisoners treated for HCV to 2000 annually was projected to reduce the HCV incidence rate to 8.69 [95% confidence interval (CI) = 8.17, 9.20] per 100 person-years (100 p.y.). Combined treatment and prevention strategies were necessary to reduce the projected incidence rate to 5.22 (95% CI = 5.13, 5.52) per 100 p.y. Considering the expected reductions in the prevalence of chronic HCV in the Australian community, incidence rate was predicted to drop to 0.93 (95% CI = 0.92, 0.98) per 100 p.y. by 2030.

Conclusions: This model, which simulates prison scenarios to inform Australia's national hepatitis C virus elimination efforts, suggests that continued direct-acting antiviral (coverage in the community combined with a moderate increase of direct-acting antiviral treatments in prisons, and introduction of improved harm reduction via opiate substitution treatment and/or needle and syringe programmes, makes hepatitis C virus elimination feasible in Australian prisons.
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http://dx.doi.org/10.1111/add.14830DOI Listing
May 2020

Clearance of hepatitis C virus is associated with early and potent but narrowly-directed, Envelope-specific antibodies.

Sci Rep 2019 09 16;9(1):13300. Epub 2019 Sep 16.

Viral Immunology Systems Program, The Kirby Institute, Sydney, Australia.

Hepatitis C virus (HCV) is one of very few viruses that are either naturally cleared, or alternatively persist to cause chronic disease. Viral diversity and escape, as well as host adaptive immune factors, are believed to control the outcome. To date, there is limited understanding of the critical, early host-pathogen interactions. The asymptomatic nature of early HCV infection generally prevents identification of the transmitted/founder (T/F) virus, and thus the study of host responses directed against the autologous T/F strain. In this study, 14 rare subjects identified from very early in infection (4-45 days) with varied disease outcomes (n = 7 clearers) were examined in regard to the timing, breadth, and magnitude of the neutralizing antibody (nAb) response, as well as evolution of the T/F strain. Clearance was associated with earlier onset and more potent nAb responses appearing at a mean of 71 days post-infection (DPI), but these responses were narrowly directed against the autologous T/F virus or closely related variants. In contrast, a delayed onset of nAbs (mean 425 DPI) was observed in chronic progressors that appear to have targeted longitudinal variants rather than the T/F strain. The nAb responses in the chronic progressors mapped to known CD81 binding epitopes, and were associated with rapid emergence of new viral variants with reduced CD81 binding. We propose that the prolonged period of viremia in the absence of nAbs in these subjects was associated with an increase in viral diversity, affording the virus greater options to escape nAb pressure once it emerged. These findings indicate that timing of the nAb response is essential for clearance. Further investigation of the specificities of the early nAbs and the factors regulating early induction of protective nAbs is needed.
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http://dx.doi.org/10.1038/s41598-019-49454-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6746763PMC
September 2019

Contribution of individual psychological and psychosocial factors to symptom severity and time-to-recovery after naturally-occurring acute infective illness: The Dubbo Infection Outcomes Study (DIOS).

Brain Behav Immun 2019 11 31;82:76-83. Epub 2019 Jul 31.

School of Psychiatry, Faculty of Medicine, UNSW Sydney, NSW, Australia.

Background: Substantial heterogeneity exists in both the severity of symptoms experienced as part of the sickness response to naturally-occurring infections, and the time taken for individuals to recover from these symptoms. Although contributing immunological and genetic factors have been previously been explored, less is known about the role of individual psychological and psychosocial factors, which may modulate the host immune response, or contribute independently, to symptom severity and duration.

Methods: Longitudinally-collected data from 484 Caucasian participants (mean age: 33.5 years; 51% women) experiencing a naturally-occurring acute infective illness enrolled in the prospective Dubbo Infection Outcome Study (DIOS) were analysed. At intake and subsequent follow-up assessments, self-report questionnaires were used to ascertain individual psychological and psychosocial characteristics and symptom information. Principal component analysis was applied to symptom data to derive endophenotype severity scores representing discrete symptom domains (fatigue, mood, pain, neurocognitive difficulties) and an overall index of severity. The contribution of individual psychological (trait neuroticism, locus of control, and illness behaviours) and psychosocial factors (relative socioeconomic advantage) to endophenotype severity at baseline were examined using multivariable linear regression models; interval-censored flexible parametric proportional hazards survival models were used to explore time to recovery (defined using within-sample negative threshold values).

Results: After controlling for time since symptom onset, greater levels of trait neuroticism consistently predicted greater symptom severity across all symptom domains (all p's < 0.015). Similarly, greater relative socioeconomic disadvantage was significantly associated with greater severity across all endophenotypes (p's < 0.025) except neurocognitive disturbance. Locus of control and illness behaviours contributed differentially across endophenotypes. Reduced likelihood of recovery was significantly predicted by greater initial symptom severity for all endophenotypes (all p's < 0.001), as well as higher levels of trait neuroticism.

Conclusions: Individual psychological and psychosocial factors contribute to the initial severity and to the prolonged course of symptoms after naturally-occurring infective illnesses. These factors may play an independent role, represent a bias in symptom reporting, or reflect increased stress responsivity and a heightened inflammatory response. Objective metrics for severity and recovery are required to further elucidate their roles.
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http://dx.doi.org/10.1016/j.bbi.2019.07.034DOI Listing
November 2019

Single-Dose Vaccination with a Hepatotropic Adeno-associated Virus Efficiently Localizes T Cell Immunity in the Liver with the Potential To Confer Rapid Protection against Hepatitis C Virus.

J Virol 2019 10 12;93(19). Epub 2019 Sep 12.

Virology Laboratory, Basil Hetzel Institute for Translational Health Research, Discipline of Surgery, University of Adelaide, Adelaide, South Australia, Australia

Hepatitis C virus (HCV) is a significant contributor to the global disease burden, and development of an effective vaccine is required to eliminate HCV infections worldwide. CD4 and CD8 T cell immunity correlates with viral clearance in primary HCV infection, and intrahepatic CD8 tissue-resident memory T (T) cells provide lifelong and rapid protection against hepatotropic pathogens. Consequently, we aimed to develop a vaccine to elicit HCV-specific CD4 and CD8 T cells, including CD8 T cells, in the liver, given that HCV primarily infects hepatocytes. To achieve this, we vaccinated wild-type BALB/c mice with a highly immunogenic cytolytic DNA vaccine encoding a model HCV (genotype 3a) nonstructural protein (NS5B) and a mutant perforin (pVAX-NS5B-PRF), as well as a recombinant adeno-associated virus (AAV) encoding NS5B (rAAV-NS5B). A novel fluorescent target array (FTA) was used to map immunodominant CD4 T helper (T) cell and cytotoxic CD8 T cell epitopes of NS5B , which were subsequently used to design a KNS5B tetramer and analyze NS5B-specific T cell responses in vaccinated mice The data showed that intradermal prime/boost vaccination with pVAX-NS5B-PRF was effective in eliciting T and cytotoxic CD8 T cell responses and intrahepatic CD8 T cells, but a single intravenous dose of hepatotropic rAAV-NS5B was significantly more effective. As a T-cell-based vaccine against HCV should ideally result in localized T cell responses in the liver, this study describes primary observations in the context of HCV vaccination that can be used to achieve this goal. There are currently at least 71 million individuals with chronic HCV worldwide and almost two million new infections annually. Although the advent of direct-acting antivirals (DAAs) offers highly effective therapy, considerable remaining challenges argue against reliance on DAAs for HCV elimination, including high drug cost, poorly developed health infrastructure, low screening rates, and significant reinfection rates. Accordingly, development of an effective vaccine is crucial to HCV elimination. An HCV vaccine that elicits T cell immunity in the liver will be highly protective for the following reasons: (i) T cell responses against nonstructural proteins of the virus are associated with clearance of primary infection, and (ii) long-lived liver-resident T cells alone can protect against malaria infection of hepatocytes. Thus, in this study we exploit promising vaccination platforms to highlight strategies that can be used to evoke highly functional and long-lived T cell responses in the liver for protection against HCV.
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http://dx.doi.org/10.1128/JVI.00202-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6744243PMC
October 2019

Severe Eosinophilic Meningoencephalitis Secondary to Suspected Neuroangiostrongyliasis with a Good Clinical Outcome.

Case Rep Infect Dis 2019 26;2019:4037196. Epub 2019 May 26.

Department of Infectious Diseases, Prince of Wales Hospital, Sydney, NSW, Australia.

has caused sporadic cases of eosinophilic meningoencephalitis in Sydney, Australia. We describe a 36-year-old man who presented subacutely with fevers, reduced level of consciousness, confusion, ophthalmoplegia, and urinary incontinence. He was diagnosed with severe eosinophilic meningoencephalitis secondary to suspected based on clinical, serological, and radiological findings. The patient was treated with albendazole and prednisolone with full neurological recovery. Management of neuroangiostrongyliasis with anthelminthic is controversial as it is thought to cause worsened outcomes through inciting an inflammatory response as a result of parasite killing. We managed to successfully treat our patient using albendazole and prednisolone and achieved a good outcome.
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http://dx.doi.org/10.1155/2019/4037196DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6556351PMC
May 2019

A method for detecting hepatitis C envelope specific memory B cells from multiple genotypes using cocktail E2 tetramers.

J Immunol Methods 2019 09 19;472:65-74. Epub 2019 Jun 19.

School of Medical Sciences and the Kirby Institute, Faculty of Medicine, UNSW Australia, Sydney, NSW 2052, Australia. Electronic address:

Hepatitis C (HCV) is a rapidly mutating RNA virus, with a strong propensity to cause chronic infection and progressive liver disease. Recent evidence has shown that early appearance of neutralizing antibodies in primary infection is associated with clearance. Little is known about the characteristics of HCV-specific B cells and their correlation with outcomes in primary infection, as there is a lack of sensitive tools for HCV-specific B cells which are present at very low frequency. We describe the development and optimisation of tetramer staining for flow cytometric detection of HCV-specific B cells using a cocktail of two recombinant HCV Envelope-2 (rE2) glycoproteins (from genotype 1a and 3a; Gt1a and Gt3a) and streptavidin dyes. The optimal weight to weight (w/w) ratio of streptavidin-phycoerythrin (PE) and rE2 proteins were determined for sensitive detection using HCV E2-specific hybridoma cell lines and peripheral blood mononuclear cells (PBMC) from HCV-infected individuals. In a cross-sectional set of PBMC samples collected from 33 subjects with either chronic infection or previous clearance, HCV E2-specific B cells (CD19CD20CD10IgDtetramer) were detected in 29 subjects (87.8%), with a mean frequency of 0.45% (0.012-2.20%). To validate the specificity of tetramer staining, 367 HCV E2-specific B cells were single cell sorted from 9 PBMC samples before monoclonal antibodies (mAbs) were synthesised, with 87.5% being reactive to E2 via ELISA. Of these mAbs, 284 and 246 clones were reactive to either Gt1a or Gt3a E2 proteins, respectively. This is a sensitive and robust method for future studies investigating B cell responses against the HCV Envelope protein.
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http://dx.doi.org/10.1016/j.jim.2019.06.016DOI Listing
September 2019

Broadly neutralizing antibodies from an individual that naturally cleared multiple hepatitis C virus infections uncover molecular determinants for E2 targeting and vaccine design.

PLoS Pathog 2019 05 17;15(5):e1007772. Epub 2019 May 17.

Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America.

Cumulative evidence supports a role for neutralizing antibodies contributing to spontaneous viral clearance during acute hepatitis C virus (HCV) infection. Information on the timing and specificity of the B cell response associated with clearance is crucial to inform vaccine design. From an individual who cleared three sequential HCV infections with genotypes 1b, 1a and 3a strains, respectively, we employed peripheral B cells to isolate and characterize neutralizing human monoclonal antibodies (HMAbs) to HCV after the genotype 1 infections. The majority of isolated antibodies, designated as HMAbs 212, target conformational epitopes on the envelope glycoprotein E2 and bound broadly to genotype 1-6 E1E2 proteins. Further, some of these antibodies showed neutralization potential against cultured genotype 1-6 viruses. Competition studies with defined broadly neutralizing HCV HMAbs to epitopes in distinct clusters, designated antigenic domains B, C, D and E, revealed that the selected HMAbs compete with B, C and D HMAbs, previously isolated from subjects with chronic HCV infections. Epitope mapping studies revealed domain B and C specificity of these HMAbs 212. Sequential serum samples from the studied subject inhibited the binding of HMAbs 212 to autologous E2 and blocked a representative domain D HMAb. The specificity of this antibody response appears similar to that observed during chronic infection, suggesting that the timing and affinity maturation of the antibody response are the critical determinants in successful and repeated viral clearance. While additional studies should be performed for individuals with clearance or persistence of HCV, our results define epitope determinants for antibody E2 targeting with important implications for the development of a B cell vaccine.
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http://dx.doi.org/10.1371/journal.ppat.1007772DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6542541PMC
May 2019

Toward DNA-Based T-Cell Mediated Vaccines to Target HIV-1 and Hepatitis C Virus: Approaches to Elicit Localized Immunity for Protection.

Front Cell Infect Microbiol 2019 3;9:91. Epub 2019 Apr 3.

Virology Laboratory, Basil Hetzel Institute for Translational Health Research, Discipline of Surgery, University of Adelaide, Adelaide, SA, Australia.

Human immunodeficiency virus (HIV)-1 and hepatitis C virus (HCV) are major contributors to the global disease burden with many experts recognizing the requirement of an effective vaccine to bring a durable end to these viral epidemics. The most promising vaccine candidates that have advanced into pre-clinical models and the clinic to eliminate or provide protection against these chronic viruses are viral vectors [e.g., recombinant cytomegalovirus, Adenovirus, and modified vaccinia Ankara (MVA)]. This raises the question, is there a need to develop DNA vaccines against HIV-1 and HCV? Since the initial study from Wolff and colleagues which showed that DNA represents a vector that can be used to express transgenes durably , DNA has been regularly evaluated as a vaccine vector albeit with limited success in large animal models and humans. However, several recent studies in Phase I-IIb trials showed that vaccination of patients with recombinant DNA represents a feasible therapeutic intervention to even cure cervical cancer, highlighting the potential of using DNA for human vaccinations. In this review, we will discuss the limitations and the strategies of using DNA as a vector to develop prophylactic T cell-mediated vaccines against HIV-1 and HCV. In particular, we focus on potential strategies exploiting DNA vectors to elicit protective localized CD8 T cell immunity in the liver for HCV and in the cervicovaginal mucosa for HIV-1 as localized immunity will be an important, if not critical component, of an efficacious vaccine against these viral infections.
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http://dx.doi.org/10.3389/fcimb.2019.00091DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6456646PMC
December 2019